Sir, my question is compressor is not going to unload, it exceed its unloaded pressure which is 7 bar and it goes continue to 8 bar and compressor trip and shows on microcontroller is “unload time over’.
There’s a problem with the pressure regulating system.
Most probably the inlet valve or the loading solenoid.
Please check the loading solenoid first. It should open control air pressure to the inlet valve when the compressor unloads.
You can check it easily by disconnecting the tube between the loading solenoid and the inlet valve.
If the compressor unloads at this time, the inlet valve is ok.
On most machines, the inlet valve is normally closed (= unload running).
Electrical power to the loading solenoid = it opens = control air to the inlet valve = inlet valve opens.
Please check if this works correctly.